Water jet propulsion means



June 3, 1969 H, v, FRENCH WATER JET PEoPULsIoN MEANS Filed oct. 18, 19e? y lllll llflllllllll 'palla IIIII'IIII'II" .I4-vae Howard Il. F7

or- @ich grifo/wey Patented June 3, 1969 3,447,324 WATER JET PROPULSION MEANS Howard V. French, 2302 Campus Court, Abilene, Tex. 79601 Filed Oct. 18, 1967, Ser. No. 676,221 Int. Cl. B63h 11/08 U.S. Cl. 60-221 10 Claims ABSTRACT F THE DISCLOSURE A water propulsion means for a water craft including a pod having an elongate, cylindrical barrel .fixed to the bottom of the craft and having front and rear ends, a hydro-dynamically contoured exterior and a central, longitudinal ow passage, a secondary venturi nozzle at the rear end of the liow passage, an annular forwardly opening scoop in the forward portion of the barrel concentric with and spaced radially outward of the forward end of the flow passage, a suction pipe communicating with the scoop and extending to the inlet side of an engine driven pump in the craft, a delivery pipe extending from the outlet of the pump to the barrel and connected with a primary nozzle arranged centrally in the llow passage and directed rearwardly into the secondary nozzle and an elongate, annular, axially extending flow augmenting sleeve concentric with and engaged freely about and projecting rearwardly from the rear end of the barrel.

For many years, boats or water craft have been propelled across or through the water by means of high pressure water jets. This manner of propelling craft has been achieved by means of motor or engine driven pumps and nozzle means receiving high pressure fluid from the pumps and directing jets rearwardly relative to the longitudinal axis of the craft. The pumps draw water from the underside of the craft and the jets of water issuing from the nozzles create a thrust or reaction to urge the craft forwardly.

Primitive means for jet propulsion of water craft have involved the arrangement of simple nozzles below the bottoms 0f the craft. In such means the nozzles are submerged and the jets issuing therefrom collide with the ambient water, creating great turbulence and very little propelling reaction. Such means have proven very ineffective and inecient.

In later water jet propulsion means for water craft, the nozzles are arranged above the surface of the water, in close proximity thereto and so that the water jets issuing from the nozzles, have considerable free lineal llow as they move rearwardly from the craft and thereby generate considerable reactive thrust. Such arrangements have proven to be quite effective and eicient, particularly in small, light, high speed craft, that is, that type of craft having planing or semi-planing hulls. Such arrangements have not proven satisfactory for use in connection with craft having displacement type hulls and which are inherently rather slow.

Another serious disadvantage with the last mentioned form of jet propulsion means resides in the fact that the jets, being exposed and above the water, create considerable undesirable noise and a great amount of splash and surface turbulence which is extremely undesirable in many situations.

In accordance with the above, there exists a great need for an eflicient and effective water jet propulsion means which is not only suitable for high speed craft, but which is also suitable for low speed craft.

An object of my invention is to provide an improved highly eihcient and effective water jet propulsion means for water craft which is `such that it can be advantageously used to effectively and eliiciently propel both high speed and low speed craft.

Another object of my invention is to provide a means of the character referred to which includes a submersible propulsion pod which is adapted to be arranged below and fixed to the bottom of a related craft whereby the disadvantages found in propulsion systems where the jets occur above the surface of the water are overcome.

A feature of my invention is to provide a means of the character referred to wherein the pod is provided with water inlet and discharge means and with flow directing and control means which cooperate to effect lineal flow of water into, through, about and from the pod in a manner to create maximum flow of water and reactive thrust for the volume of water pumped into and through -the construction.

The foregoing and other objects and features of my invention will be fully understood from the following detailed description of typical preferred forms and applications of my invention, throughout which description reference is made to the accompanying drawings, in which:

FIG. l is an elevational view of a typical water craft with my new propulsion means related to it;

FIG. 2 is an enlarged detailed longitudinal sectional view of the propulsion pod that I provide;

FIG. 3 is a rear end view of the pod taken as indicated by line 3-3 on FIG. 2; and,

FIG. 4 is a longitudinal view of a portion of another form of my invention with portions shown in section.

The water propulsion means that I provide is adapted to be related to a water craft A and includes generally, a prime mover B, such as an internal combustion engine, Iarranged within the craft, a pump C, such as a centrifugal pump, within the craft and driven by the prime mover and a propulsion pod D fixed to the bottom 10 of the craft and connected with the inlet and outlet sides 11 and 12 of the pump. In practice, a suitable valve means V can be provided between the pod lD and pump C to control the iiow of water through the means.

Since the craft A, prime mover B, pump C and valve means V can vary widely without affecting the novelty of this invention, I have elected to illustrate these parts and/ or portions of the propulsion means in a general or diagrammatic manner and will not burden this disclosure with further unnecessary detailed description thereof.

The pod D that I provide is an elongate unitary structure and includes an elongate, horizontally extending barrel 20, cylindrical in cross-section and iixed to the bottom 10 of the craft A by means of a iiat mounting plate 21. 'The mounting plate 21 is, in practice, formed integrally with the barrel at the upper side thereof. The mounting plate 21 is fixed to the bottom of the craft by suitable fasteners 22.

The barrel 20 is arranged below the bottom of the craft with its longitudinal axis extending parallel with the longitudinal axis of the craft and so that it has or defines front and rear ends.

The barrel 20 has a central longitudinal flow passage 23 and a contoured or cambered exterior surface 24. The interior surface of the ow passage 23 and the contoured exterior surface 24 of the barrel cooperate to define an annular foil, the cross-section of which is similar to a modified Clark Y airfoil, the function of which will be later described.

The dow passage 23 opens forwardly, is straight and unobstructed throughout its longitudinal extent and is connected at its rear end with a reduced rearwardly extending, rearwardly opening venturi secondary nozzle 25.

In practice, the nozzle 25 can be in the nature of an extension formed integrally with and continuing rearwardly from the structure defining the ow passage 23.

The forward end portion of the barrel is provided with an annular forwardly and radially outwardly opening channel defining an inlet scoop 26. The scoop 26 has a substantially flat rearwardly and upwardly inclined rear wall of surface 27 upon which water rushing rearwardly into the scoop impinges. The inclined surface 27 directs the water impinging upon it upwardly and rearwardly in the scoop. The scoop 26 is further defined by a radially outwardly disposed annular side surface 28 extending forwardly from the inner periphery of the surface 27, to the forward end of the barrel and about the forward portion of the ow passage 23.

The surface 28 can, as illustrated, be cambered longitudinally so that the cross-section of the portion of the pod defining the surface 28 and forward end of the liow passage A23 is a Clark Y type foil which serves to induce and control the flow of water into the scoop.

An inlet or suction pipe 29 communicates with the upper rear portion of the scoop, adjacent the rear surface thereof and extends upwardly through the barrel, mounting plate 21, and opening 30 provided in the bottom 10 of the craft A and, thence, into the interior of the craft where it is suitably connected with the inlet 11 of the pump C or the valve means V as by means of a suction hose 31.

In addition to the foregoing, the pod D is provided with a primary nozzle 32 concentric with and opening rearwardly at the rear end of the flow passage 23, forward of the open rear end of the secondary nozzle 25.

The nozzle 32 is connected with and receives water from a downwardly and rearwardly turned delivery pipe 33, which pipe extends downwardly from within the craft A, through the opening 30 in the bottom 10 of the craft and, thence, through the pod and into the ow passage therein. The upper end of the pipe 33 occurring within the craft A is suitably connected with the pump C or with the valve means V by means a suitable delivery hose 34.

In practice, a suitable faring member 35 can be provided at and about that a portion of the pipe 33 extending radially through the ow passage 23 to materially reduce any adverse turbulence and interference with the free flow of water through the passage, caused by the presence of the pipe 33 therein.

Finally, and in addition to the foregoing, the pod D is provided with an elongate, annular ow augmenting venturi sleeve or ring 36 concentric with the central longitudinal axis of the barrel and arranged at the rear end of the barrel with its forwardly opening front end portion occurring in radial spaced relationship about the secondary nozzle 25 and/or rear end portion of the barrel in radial spaced relationship therefrom and with its rearwardly opening rear end portion extending rearwardly from or beyond the rear end of the nozzle 25.

The ow augmenting venturi sleeve has a radially inwardly and rearwardly convergent, curved, flow accelerating ow passage 37 and a contoured or cambered exterior surface 38. The exterior surface 38 is contoured so as to streamline the sleeve and so that a minimum resistance to the free iiow of Water axially rearwardly about the sleeve is generated.

The sleeve 36 is supported and carried by a central, longitudinally extending, vertical vane-like web 39 depending downwardly from the mounting plate 21 and rearwardly from the rear portion of the barrel, as clearly illustrated in the drawings.

If necessary, or desired, additional, circumferentially spaced support webs can be provided between the rear portion of the barrel and the ring, and, if desired, the web 39 can be eliminated altogether and the sleeve can be supported by circumfrentially spaced webs between the rear end portion of the barrel and the sleeve, as illustrated at 39 in FIG. 4 of the drawings.

1f desired, suitable guard means 40 can be provided at the forward end of the pod to prevent foreign matter whichmight plug or clog the construction from entering the forward ends of the inlet scoop and flow passage. In

the case illustrated, the means 40 is shown as involving four circumferentially spaced, radially inwardly and forwardly convergent metal detiecting bars 41, the rear ends of which are fixed to the forward outer end portion of the barrel at or adjacent to the outer forward edge of the scoop 26.

In operation, the pump C is driven by the motor B and water is drawn rearwardly into the scoop 26, through the suction 29 and into the pump. The water discharged from the pump is conducted downwardly through the pipe 33 and rearwardly into the nozzle 32. The nozzle 32 directs a high pressure, high velocity primary jet of water rearwardly into and through the secondary venturi nozzle 25. The primary jet flowing through the venturi nozzle 32 induces flow of water into and rearwardly through the ow passage 23, which rearward ow of water is accelerated by the venturi nozzle and by the primary jet as it enters the nozzle 25 and joins the primary jet. The waters flowing from the nozzle 32 and through the flow passage 23, when combined, issue from the secondary nozzle 25 as the secondary jet of considerably greater mass and only slightly less velocity than the primary jet. j

The rearwardly flowing column of water drawn into and through the flow passage 23 of the barrel by the primary jet owing through the secondary nozzle 25 establishes a limited reaction and forward thrust. Further, the primary jet, as it issues from the nozzle 32 creates a reaction and forward thrust. Still further, the secondary jet, as it issues from the nozzle 25, creates yet another reaction and forward thrust in and through the construction.

The above-noted reactions and thrusts are cumulative.

As the barrel moves forwardly through the Water, the ambient water forward of the pod is rammed into and through the flow passage 23. This ramming of water into and through the ow passage supplements the action of the primary jet and, in effect, supercharges the secondary nozzle 25 and greatly accelerates the velocity of the secondary jet.

The water adjacent to and iowing longitudinally about the exterior surface of the barrel and which is parted from the central rearwardly owing column of water by the leading edge of the barrel, is forced to ow a greater distance before it reaches the rear end of the barrel and/or nozzle 25 to join with the centrally owing column of Water, now the secondary jet. In doing so and as a result of the modied Clark Y foil configuration, several forces come into play. First, a positive pressure is created over and about the forward end portion of the barrel as the water is separated by the annular leading end portion of said barrel. Second, the water, thus displaced, and flowing or rushing rearwardly about the exterior of the barrel is greatly accelerated as it moves rearwardly towards and to the trailing edge of the foil configuration, that is, to the rear end of the barrel and/or nozzle 25. Third, a negative pressure is created in the ambient waters about the rear portion of the barrel by the noted accelerated iiow of water and, as a result thereof, additional water is drawn into and joins the noted slip-stream of water about the exterior of the barrel. Fourth, the point or area of greatest impact pressure is over and about the forward end portion and/or leading edge of the barrel, and a positive pressure is created about the inlet of the inlet scoop 26, which pressure is picked up by the inlet scoop and serves to supplement and, in effect, supercharge the pump C.

The water flowing into the inlet scoop 26 is further accelerated by the modified Clark Y configuration established by the surface 28 thereof. The accelerated iiow of water in the scoop, upon impinging on the upwardly and rearwardly inclined rear surface 27 of the scoop, is effectively forced upwardly and into the suction pipe 29.

The secondary jet issuing from the nozzle 25 and the rear end of the barrel is directed centrally into and rearwardly through the rear portion of the ow augmenting venturi sleeve 36. At the same time, the accelerated flow stream about the exterior of the barrel and the additional waters picked up by it enter the forward end portion of the sleeve 36 and flow rearwardly therethrough to be accelerated thereby and to join the secondary jet in the rear portion thereof. The waters owing into and through the sleeve 36 combine to establish one forcefully directed jet of materially greater mass and only slightly less velocity than the secondary jet issuing from the rear end of the sleeve. The force of this third or :final jet exerts an equal and opposite force onto and through the pod construction to thrust the pod construction and the craft with which it is related, forwardly.

From the foregoing, it will be apparent that the pod construction is such that a large volume and massive ow of water is effectively and efficiently moved and directed with a relatively small high velocity primary jet of water and in such a manner that the work energy of the primary jet is most eiliciently and effectively converted to reactive forces tending to propel the construction forwardly through the Water.

In the form of the invention shown in FIGS. 1, 2 and 3 of the drawings, the pod D is mounted in xed position on the craft A. Accordingly, the craft is provided with a rudder 50, rearward of the discharge end of the pod to deflect the jet stream issuing from the pod in such a manner as to control the direction of the craft.

Since the pod D is fixed relative to the craft, it can only serve to propel the craft forwardly when functioning in a normal manner.

In order to move or propel the boat rearwardly, I provide the valve means V noted above. The valve means V is such that the direction of ow into and out of the pipes 29 and 33 of the pod construction can be reversed. By reversing the ow through the pipes 29 and 33, by means of the valve V, the pipe 33 becomes a suction pipe and the pipe 29 becomes a delivery pipe, directing a high pressure stream of water into the scoop 26, which water flows forwardly out of the scoop to thrust and propel the structure rearwardly.

The above-noted reverse flow is extremely inefficient, but is adequate to provide necessary maneuverability of the craft.

In the form of the invention illustrated in FIG. 4 of the drawings, the pod D is swivally or rotatably mounted on the bottom of the craft A' by means of a suitable sealed swivel mounting means 60. With such a mounting means the direction of the craft can be advantageously controlled by simply turning the pod, and a rudder, such as is required in connection with the first form of the invention, is not required. Further, in the second form of the invention, the pod can be turned 180 to effect rearward propulsion of the craft. Accordingly, a valve means, such as referred to above, need not be provided.

The second form of the invention, illustrated in FIG. 4 of the drawings, further distinguishes from the first form of the invention by terminating the forward end of the central ow passage 23 in the barrel rearward of the forward end of the barrel and arranging the inlet scoop 26 within the forward end of the barrel so that it opens forwardlyl and radially inwardly, rather than radially outwardly, as in the first form of the invention.

With such a relationship of parts, it is necessary that the opening at the forward end of the barrel be substantially greater in diametric extent than the open forward end of the ow passage and so that the scoop 26 and the pump will not function to starve the supply of water flowing into and through the flow passage and secondary nozzle of the construction.

The arrangement of the inlet scoop 26 in this second form of the invention, when the pump is operating, induces the rearward flow of an annular column of water through the forward open end of the barrel and into the scoop.

This annular ow of water rearwardly into the scoop induces the rearward flow of a central column of water into and through the flow passage 23'. Such a function is extremely desirable in those cases where the craft is a relatively slow speed craft and a sufiicient ram effect to charge the system, as it moves forwardly through the water, is not established.

It is to be noted that there are no moving parts within the pod and that the structure is, therefore, extremely quiet, smooth, safe-in-operation, and can be advantageously used in any and all situations where such characten'stics or features are deemed necessary and/or desirable.

While I have restricted this disclosure to a structure applicable to a vessel or boat for the purpose of preferably the boat, it is to be understood and it will be apparent that the structure can be employed to propel, agitate and mix with liquids along a pipeline, conduit or canal, or within a tank or vat by simply mounting the pod in the ow path within such liquid conducting means or within a tank, or the like.

Having described my invention, I claim:

1. In combination, an elongate water craft with front and rear ends, a bottom and an interior, a prime mover in the interior of the craft, a pump with inlets and outlets in the interior of the craft and driven by the prime rnover and an elongate, submersible propulsion pod with front and rear ends mounted on the bottom of the craft to occur in water therebelow and connection with the pump, said pod including an elongate cylindrical barrel with a forwardly opening central longitudinal ow passage, an inlet scoop at the forward end of the barrel and occurring radially outward from the flow passage, -a suction pipe between the scoop and the inlet of the pump, a rearwardly directed primary nozzle arranged centrally of the ow passage at the rear end thereof, a delivery pipe between the outlet of the pump and the primary nozzle, a secondary venturi nozzle concentric with and continuing rearwardly from the flow passage and primary nozzle and having a rear discharge end smaller than the flow passage and larger than the primary nozzle and an elongate flow augmenting venturi sleeve concentric with and larger in diameter than the rear end of the barrel and having a forwardly opening forward portion in radial spaced relationship about the rear end portion of the barrel and the secondary nozzle and a rearwardly opening rear portion extending rearwardly from the secondary nozzle.

2. A structure as set forth in claim 1 wherein said inlet scoop is an annular forwardly and radially outwardly opening scoop formed in the forward end portion of the barrel.

3. A structure =as set forth in claim -1 wherein said scoop is an annular forwardly and radially inwardly opening scoop formed in the inner end portion of the barrel.

4. A structure as set forth in claim 1 wherein said inlet scoop is an 'annular forwardly sand radially outwardly opening scoop formed in the forward end portion of the barrel, said scoop having a substantially flat, rearwardly and upwardly inclined back surface and la substantially radially outwardly disposed inner side surface, said suction pipe communicating with the scoop adjacent the upper rear portion of the rear surface.

5. A structure as set forth in claim 1 including, an opening in the bottom of the craft, mounting means mounting the pod to the bottom of the craft and overlying the opening, said pipes extending from the barrel upwardly through the mounting means and into the interior of the craft to connect with the pump.

6. A structure as set forth in claim 1 including, an opening in the bottom of the craft, mounting means mounting the pod to the bottom of the craft and overlying the opening, said pipes extending from the barrel upwardly through the mounting means and into the interior of the craft to connect with the pump, said mounting 7 l means being a sealed swivel structure pivotally supporting the pod for free rotation in excess of 180 about a vertical axis.

7. A structure as set forth in claim 1 including, ian opening in the bottom of the craft, mounting means mounting the pod to the bottom of the craft and overlying the opening, said pipes extending from the barrel upwardly through the mounting means and into the interior of the craft to connect with the pump, said inlet scoop being an annular forwardly and radially outwardly opening scoop formed in the forward end portion of the barrel.

' 8. A structure as set forth in claim 1 including, an opening in the bottom of the craft, mounting means mounting the pod to the bottom of the craft and overlying the opening, said pipes extending from the barrel upwardly through the mounting means and into the interior of the craft to connect with the pump, said mounting means being a sealed swivel structure pivotally supporting the pod for free rotation in excess of 180 about a vertical axis, said inlet scoop being Ian annular forwardly and radially outwardly opening scoop 'formed in the forwardend portion of the barrel.

9. A structure :as set forth in claim 1 including, an opening in the bottom of the craft, mounting means mounting the pod to the bottom of the craft and overlying the opening, said pipes extending from the barrel upwardly through the mounting means and into the interior of the craft to connect with the pump, said inlet scoop being an annular forwardly and radially outwardly opening scoop formed in the forward end portion of the barrel, said scoop having a substantially flat, rearwardly and upwardly inclined back surface and a substantially radially outwardly disposed inner side surface, said suction pipe communicating with the scoop adjacent the upper rear portion of the rear surface.

10.` A structure as set forth in claim 1 including, an opening in the bottomA of the craft, mounting means mounting the pod to the bottom of the craft and overlying the opening, said pipes extending from the barrel upwardly through the mounting means and into the interior of the craft to connect with the pump, said mounting means being a sealed swivel structure pivotally supporting the pod for free rotation in excess of 180 about a vertical axis, said inlet scoop being =an annular forwardly and radially outwardly opening scoop formed in the forward end portion of the barrel, said scoop having a substantially at, rearwardly and upwardly inclined back surface and a substantially radially outwardly disposed inner side surface, said suction pipe communicating with the scoop adjacent the upper rear portion of the rear surface.

References Cited nUNITED STATES PATENTS i Morize --11 X AL LAWRENCE SMITH, Primary Examiner.

U.S. C1. X.R. 10S- 262; 11S-12, 14; Z39-265.17, 265.9194 

